TruPhone, Top VoIP Company 2008: FierceVoIP, Fierce 15

Truphone

Where it's based: London, England
When it was founded: 1999
Website: www.truphone.com 

Why it's Fierce: Truphone decided to power its way around the me-too mobile VoIP pack by buying roaming operator SIM4travel. While it is still in the me-too free client/lowest-rate voice game, it hasn't been afraid to fight established cellular operators in court to get the settlements it wants. 

On the technology side, Truphone has developed clients for a variety of phones, including the BlackBerry and iPhone; Truphone had the first Internet telephony app for the iPhone on the iStore, er, Apple App Store.  The company has a carrier-grade, global telephony operator infrastructure on the backend to handle up to 40 million calls worldwide that includes a global network of SIP gateways, a Nokia Siemens Networks mobile network Home Location Register (HLR) and a GSM identifier.